Robot system controlling method, program, recording medium, robot system, and diagnosis apparatus

Abstract

A method of controlling a robot system including an articulated robot and a control device is provided. The articulated robot includes links connected by joints, motors configured to drive the joints respectively, and detection devices configured to detect rotation amounts of the joints respectively. The control device controls the motors. The method includes the steps of, by the control device, recording movement information of the joints based on outputs of the detection devices; when detecting an abnormality in the operation of the articulated robot, determining presence or absence of a failure in the articulated robot based on the movement information recorded in at least a period from before detection of the abnormality until detection of the abnormality; and specifying a failure portion of the articulated robot if it is determined that there is a failure in the articulated robot in the step of determining.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a method of controlling an articulated robot including a plurality of motors which drive joints connecting links respectively, and a plurality of detection devices which detect rotation amounts of the joints connecting the links respectively.[0003]2. Description of the Related Art[0004]An articulated robot, in which both ends of respective links are connected by rotary joints whereby the links are able to perform a bending movement, has been widely used. In the articulated robot, as some of the links have torsional joints which rotate in a torsional direction within a cross-section vertical to a longitudinal direction of the link, the articulated robot is able to perform complicated movement such as six-axis motion or seven-axis motion similar to that of a human arm.[0005]An articulated robot may interfere with another object in any situations including test operation, teaching, and actu...

AI Technical Summary

Benefits of technology

The present invention provides a method for controlling a robot system that can accurately estimate the load state of each joint and determine the possibility of damage in each joint with less error. This helps to prevent damage to the robot caused by interference with other objects.

Problems solved by technology

An articulated robot may interfere with another object in any situations including test operation, teaching, and actual operation.

When an articulated robot interferes with another object, there is a possibility that an overload is caused in a particular joint so that an origin is shifted, or that a damage is caused in a part such as a reduction gear, a bearing, or the like constituting the joint.

If an articulated robot is operated in a state where an origin is shifted in a joint or a part of a joint is damaged, a work may be dropped due to deterioration in the operation accuracy, power consumption may increase, or another articulated robot may be interfered.

In the robot system of Japanese Patent Application Laid-Open No. 11-202914, it is impossible to accurately determine a load state of each of the joints of the articulated robot.

As a large difference is caused between the maximum loads placed on the two joints due to interference according to the rotational directions and the load states of the two joints before the interference, broken conditions of the parts cannot be determined accurately.

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